Fiber cushions (i.e., seats and backrests) are more durable, more breathable, less costly, and more readily recyclable than foam, and do not emit gases during processing. It is known to make fiber-filled cushions from a mixture of high melting point and low melting point fibers by heating the mixture in an oven so as no soften the low melting fibers (hereafter bonding fibers) and unite them with the high melting fibers (hereafter matrix fibers) at their points of intersection, and then cooling the mixture sufficiently to bond the bonding fibers to the matrix fibers.
Copending U.S. patent application No. 08/214,510 filed Mar. 18, 1994, now U.S. Pat. No. 5,482,665, in the name of P. Gill, and assigned to the assignee of the present invention describes a unique process and apparatus for heating and cooling a mixture of high and low melting fibers to make a cushion by passing hot and cool air, respectively, through the fiber mass. One of the shortcomings of the U.S. Ser. No. 214,510 process is that the time required to complete the heating-cooling cycle is determined by the time it takes to properly heat and cool the thickest or the densest sections of the cushion which have reduced air flow therethrough.